Love Clipart Images Free Download Best On. When in gliding flight the upward aerodynamic force is equal to the weight In gliding flight no propulsion is used the energy to counteract the energy loss due to aerodynamic drag is either taken from the potential energy of the bird resulting in a descending flight or is replaced by rising air currents thermals referred to as soaring flight For specialist soaring birds obligate soarers the decision to engage in flight are strongly related to atmospheric conditions that allow individuals to maximise flight efficiency and minimise energetic costs.

Birds use flight to obtain prey on the wing for foraging to commute to feeding grounds and to migrate between the seasons It is also used by some species to display during the breeding season and to reach safe isolated places for nesting Flight is more energetically expensive in larger birds and many of the largest species fly by soaring and gliding without flapping their wings as much as possible Many physiological adaptations have evolved that make flight more efficient Birds that settle on isolated oceanic islands that lack ground based predators often lose the ability to fly This illustrates both flight s importance in avoiding predators and its extreme demand for energy